What causes infertility?

About a third of the time, infertility can be traced to a cause within the woman. In another third of cases, it is the man who faces infertility. The rest of the time, it is because both partners have infertility issues or because no cause is found. However, there is no single cause of infertility because a successful pregnancy is a multistep chain of events.

To put it simply, achieving pregnancy includes the following steps: A woman’s ovaries must be able to release a viable egg, which then must be capable of traveling down the fallopian tube. The man must be able to ejaculate, and his sperm must be able to travel to the fallopian tube. The sperm and egg must unite to fertilize the egg. And the fertilized egg must implant inside the uterus and be nurtured by the body to allow the fetus to develop and grow until it is ready for birth. Problems with any of these steps can mean infertility. Given all of the above factors that must work properly in order for conception to occur, combined with the need for adequate hormone levels and proper physiology, it is a miracle women ever get pregnant at all.

The modern increase in the incidence of infertility may be due to any number of reasons or perhaps a combination of reasons: Couples are having children at a later age than previous generations (the proportion of first births to women aged 30 and older has increased more than fourfold since 1975, from 5 to 24 percent in 2006). Prolonged use of hormonal contraception, various environmental influences, genetic disorders, increased levels of stress and additional sexually transmitted diseases could all be contributing factors. In short, there are many theories surrounding the cause of higher infertility rates today, but there are no definitive answers.

Female infertility

Carmen shares her experience of finding a medical diagnosis for her infertility:

“After one year of trying to conceive, I finally had some blood work done and discovered I was hypothyroid. My doctor was convinced that this was the cause of my infertility. I began taking a pill to regulate my thyroid levels, but we still did not conceive. We went to another doctor at this point, and by now my husband was more involved because the time lapse since our first pregnancy indicated that things were certainly different this time around. This doctor looked at my NFP charts and said I had a luteal phase deficiency (meaning that the period of time in a woman’s menstrual cycle between ovulation and the possible implantation of an embryo was too short and could potentially impede an embryo from properly implanting) and thus prescribed progesterone suppositories. He was very positive, and I remember feeling like we had found the solution; I was so sure we were going to get pregnant right after I started the medication. The answers seemed to fit and were relatively easy to fix so we thought everything would be fine. However, this was not the answer either, and I think the fact that my husband and I had so much hope was one of the hardest part of the journey.”

Although this is by no means an exhaustive list, below are the leading causes of infertility in women:

Endometriosis — occurs when the uterine tissue implants and grows outside of the uterus, often affecting the function of the ovaries, uterus, and fallopian tubes. This can lead to scarring and inflammation. Pelvic pain and infertility are common in women with endometriosis.

Polycystic ovary syndrome (PCOS) — results from too much androgen hormone production, which affects ovulation. Ovaries may not release an egg regularly or may not release a viable, healthy egg. Among women who have PCOS, even when a healthy egg is released and fertilized, the uterus may not be receptive to implantation of a fertilized egg.

Ovulation disorders — occur when disruption in the part of the brain that regulates ovulation causes low levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Even slight irregularities in the hormone system can prevent the ovaries from releasing eggs (anovulation).

Elevated prolactin (hyperprolactinemia) — due to high levels of the hormone prolactin, which stimulates breast milk production. This may affect ovulation in women who aren’t pregnant or nursing.

Early menopause (premature ovarian failure) — is defined as the absence of menstruation and the early depletion of ovarian follicles before age 40. Certain conditions are associated with early menopause, including immune system diseases, radiation or chemotherapy treatment and smoking.

Fallopian tube damage or blockage — usually results from inflammation of the fallopian tube (salpingitis). Tubal damage may result in a pregnancy in which the fertilized egg is unable to make its way through the fallopian tube to implant in the uterus (ectopic pregnancy).

Uterine fibroids — are basically benign tumors in the wall of the uterus, common in women in their thirties and forties. Rarely, they may cause infertility by blocking the fallopian tubes. More often, fibroids interfere with proper implantation of the fertilized egg.

Thyroid problems — includes disorders of the thyroid gland, either too much thyroid hormone (hyperthyroidism) or too little (hypothyroidism), can interrupt the menstrual cycle and cause infertility.

Male infertility

The male fertility process involves the production of mature sperm that must reach and fertilize the egg. Although it may seem to be a simpler process than female fertility, male fertility also requires many conditions to be met. The male must be able to have and sustain an erection, have enough sperm and semen to carry the sperm to the egg, and have sperm of the right shape that move in the right way. A problem meeting any of these conditions contributes to infertility.

Less medical research has been done in the area of male infertility, partly because doctors will tend to recommend Assisted Reproductive Technology (ART) or insemination as the solution to male infertility. As a result, there are fewer treatment options to assist the underlying medical conditions of male factor infertility.

Again, though not exhaustive, here are some common causes of male infertility. Most cases of male infertility are due to problems with the sperm, such as:

Impaired shape and movement of sperm — occurs when sperm is unable to reach or penetrate the egg due to abnormal sperm structure (morphology) or impaired sperm mobility (motility).

Low sperm concentration — is indicated by a count of ten million or fewer sperm per milliliter of semen. In many instances, no cause for reduced sperm production is found. When sperm concentration is less than five million per milliliter of semen, genetic causes could be involved.

Varicocele — occurs when a varicose vein in the scrotum that may prevent normal cooling of the testicle, leading to reduced sperm count and motility.

Undescended testicle — occurs when one or both testicles fail to descend from the abdomen into the scrotum during fetal development. Because the testicles are exposed to the higher internal body temperature, sperm production may be affected.

Testosterone deficiency (male hypogonadism) — can result from disorders of the testicles themselves or from an abnormality affecting the hypothalamus or pituitary gland in the brain that produces the hormones that control the testicles.

Genetic defects — include instances like Klinefelter’s syndrome, which is when a man has two X chromosomes and one Y chromosome instead of one X and one Y. This causes abnormal development of the testicles, resulting in low or absent sperm production and possibly low testosterone.

Infections — may temporarily affect sperm motility. Repeated bouts of sexually transmitted diseases (STDs), such as chlamydia and gonorrhea, are most often associated with male infertility. These infections can cause scarring and block sperm passage. If mumps, a viral infection usually affecting young children, occurs after puberty, inflammation of the testicles can impair sperm production. Inflammation of the prostate (prostatitis), urethra, or epididymis also may alter sperm motility.

Impaired delivery of sperm — may include sexual issues such as erectile dysfunction, premature ejaculation, painful intercourse (dyspareunia), or psychological or relationship problems; retrograde ejaculation (when semen enters the bladder during ejaculation rather than emerging out through the penis); blockage of epididymis or ejaculatory ducts; no semen (ejaculate) resulting from spinal cord injuries or diseases; anti-sperm antibodies, which weaken or disable sperm; cystic fibrosis, which causes a missing or obstructed vas deferens.

In some cases, health care providers cannot determine a cause for infertility in the man or woman, while some known causes of infertility lack any clear-cut treatments.

Carmen relates the challenges of discovering multiple reasons for their difficulty conceiving and the lack of straight-forward treatment options:

“After a few more months, we did more testing, and my husband, Alex, was tested via a morally-acceptable semen analysis for the first time. This was the first time we realized there might be something wrong with him and not just me. We were both frustrated at how much time had passed, how we had seemingly wasted time, as well as how the addition of Alex’s medical issues complicated the situation. More time elapsed, and after two years, we went to see an Ob/Gyn who put me on Clomid, which is a prescription drug that assists with fertility. My husband began taking a bunch of supplements, started seeing several urologists, and also was prescribed Clomid as well as antibiotics. After taking all these pills, his test results continued to come back the same. Recently, after more than two and a half years of infertility, Alex underwent surgery to correct a varicocele to see if that would help our chances of conceiving.”

Secondary infertility

Secondary infertility is defined as the inability to become pregnant, or carry a pregnancy to term following the birth of one or more biological children. Those who suffer from secondary infertility often feel like they are especially alone, as if they do not belong in either the fertile or infertile world. The added pressure of feeling like others may judge you for desiring more children when you already have one or more children is a common source of stress. There are even some who feel that secondary infertility is not “real” infertility.

Carmen shares her experience with secondary infertility after the birth of her two children:

“Secondary infertility begs the question of whether we are forcing God’s plan. Are we simply not meant to have children, or more than what we have? As my friends continued to have more children, I have been told I am “falling behind,” and it’s hard to hear those types of comments. In addition to having a strong desire or calling to raise more of God’s children, there is the added pressure of children asking for a sibling. Every night without fail, our sweet daughter, Monica, asks for a brother or sister, if it is God’s will. Her “faith like a child” is an example to us, and she has the faith I need. This fear of not being able to give our child a brother or sister is common among those how suffer from secondary infertility. I was never too bothered by the fact that I’m an only child, but I have never wanted the same for my own family. I have to remind myself that just because I think something is best does not mean that it is what God thinks. My mother wanted a huge family and only had one child. I also try to remember that there are some very important “onlys” in our faith, starting with Jesus himself and his mother Mary, as well as John the Baptist. All of them played a role in our salvation, and we should not minimize the impact of one child, one life.”

How is infertility diagnosed?

Although the inability to achieve a pregnancy within a twelve-month period may be an indication of possible infertility, only a health care provider can provide a diagnosis of infertility. If you suspect you may have infertility issues, we suggest seeing your doctor and expressing your interest in finding the underlying causes of your infertility. As with any disease, it is not enough to simply treat the symptoms of infertility. Doctors should first of all ensure that the couple is timing intercourse correctly. (Natural Family Planning, for example, is one method used to assess optimum fertility in women.)

Tests to diagnose the causes of fertility include (but are not limited to):

Blood work, physical examination, and morally-obtained semen sample for men to determine sperm viability; and

Blood work and assessment of the competence of the uterus, ovaries, and fallopian tubes via imaging techniques.

Angelique explains the process she and her husband underwent to get medical answers as to why they were not conceiving:

“Because of my textbook 28-day cycles and because we practiced NFP and knew we were timing intercourse correctly, we decided to speak to my gynecologist after about six months of trying to conceive. He analyzed our NFP charts and said everything looked good and that it would likely just be a matter of time. We continued to press him, however, and he agreed to have my husband and me get blood drawn. When these produced results that did not indicate any issues, my husband had a semen analysis and I had a hysterosalpingogram (a special ultrasound in which contrast is injected into the uterus to check if the fallopian tubes are open or blocked). Everything checked out okay with these tests, too. It was frustrating to have the nondiagnosis of ‘unexplained infertility’ and not have recourse to any treatments because there were seemingly no underlying issues.”

As we can see from the varied diagnoses and experiences of infertility, no two journeys are quite the same, yet we are united in our quest for medical solutions and spiritual guidance.

— Carmen Santamaria is an attorney with two biological children, Monica and Antonio Javier, and two adopted children, Victoria and Daniel.

— Angelique Ruhi-Lopez is a freelance writer and blogger. She has one adopted child, Emmanuel, and three biological children, Sebastian, Madeleine, and Anabella.

CCL’s award-winningFamily Foundationsis the only NFP magazine in the United States and is a great source of support. Visithereto learn more.